We report the results of a photometric multisite campaign devoted to HD 35914, the variable central star of the Planetary Nebula IC 418. From the analysis of 120 hours of data acquired with a variety of techniques, we find that HD 35914 exhibits two distinct kinds of variability: irregular light modulation with a time scale of days, as well as

We obtain the time delay between the arrival time of the A and B images of the QSO 0957+561. The results of applying two different methods (the discrete cross-correlation function and the dispersion estimation technique) to the observed light curves of the A and B images are presented. The adopted value (time delay) is of Delta tau BA = 424 +/- 3

We have measured the brightness of the optical counterpart of the black hole X-ray binary Nova Sco 1994 (GRO J1655-40) during 40 nights between 1995 May 3 and July 27. From our observations and data from the literature we refine the orbital period to be 2.620 40+/-0.000 98 d. We model the R-band light curve as primarily arising from an X-ray heated

IAUC 6621 available at Central Bureau for Astronomical Telegrams.

Not Available

Broadband UBVRI and narrowband H alpha and continuum images have been obtained for the Hickson compact group HCG 31 as part of an ongoing program devoted to the study of the star formation properties of galaxies in these groups. A spatially resolved analysis for the (U-B), (V-I), and (B-I) color maps has been performed, as well as for the U band, H